   `run-driver` and `connect-driver` may accept."
   ([type]
    (boot-driver type {}))
-  ([type {host :host :as opt}]
+  ([type {:keys [host] :as opt}]
    (cond-> type
      true       (create-driver opt)
      (not host) (run-driver opt)

                     path-browser
                     driver-log-level]}]]

  (let [{:keys [type port]} @driver
        log-level           (or log-level :all)
        path-driver         (or path-driver (get-in defaults [type :path]))

        _ (swap! driver drv/set-browser-log-level log-level)
        _ (swap! driver drv/set-path path-driver)

  [driver]
  (util/connectable? (:host @driver)
                     (:port @driver)))

;;
;; predicates
